1. Field of the Invention
The present invention relates to a method for producing a coffee beverage, and more particularly a method for producing a coffee beverage by which brewed coffee may be given robustness and mildness to be easy to drink without losing the beauty of its appearance.
2. Description of Related Art
Various methods for brewing coffee are known, such as a drip method, a siphon method, an espresso method and a water drip method, under which raw beans are used after being roasted and ground up till they have appropriate graininess, and a method under which a commercially available instant coffee powder or coffee concentrate is dissolved in cold or hot water. When any of these methods is tried, obviously, brewed coffee is dark brown in color without turbidity.
Brewed coffee may be served in various ways; it may be varied based on whether to have it black with no sugar or to add cream and/or sugar optionally, whether it is brewed strongly or weakly, or any other conditions. In particular, espresso coffee brewed in the espresso method is known as strong coffee. The reason why espresso coffee is strong is as follows: coffee beans are roasted and ground into a fine powder, and pressure is applied to the powder to brew coffee instantaneously, thereby forming brown fine froth covering the surface of the brewed coffee when it is poured into a coffee cup. Such coffee tastes much stronger than strongly dripped coffee does, and gives off more of its own flavor.
In general, coffee brewed on the normal or weak side, which is easy to drink, is preferred, and whether to have it black or creamed/sweetened tends to depend on how each individual likes. Strongly dripped black coffee or espresso coffee offers pleasure from a savor and aroma intrinsic in coffee, but because of being strong and bitter, it is rather hard to drink, and thus there is a tendency among many people not to prefer such coffee. Therefore, with a growing trend to pursue gourmet in recent years, there have been offered a wider range of coffee beverage variations provided by making authentic coffee mild and easier to drink.
Well-known examples of such coffee are cafxc3xa9 au lait, which is so-called white coffee, cafxc3xa9 latte prepared by pouring espresso coffee into milk simultaneously frothed and warmed by a steamer, cappuccino prepared by putting warmed and well-frothed milk on strongly dripped coffee or espresso, and the like.
Specifically, as for the technique for lessening bitterness and adding mildness to coffee by using a milk ingredient, Patent Literature 1, which will be listed below, discloses cafxc3xa9 latte and cappuccino which are espresso beverages containing steamed milk. As shown in FIG. 4, cafxc3xa9 latte and cappuccino according to the Patent Literature 1 are obtained by pouring coffee supplied from a line 52 and frothed milk supplied from a milk tube 100 simultaneously into a serving cup 54. It should be noted that the coffee supplied from the line 52 is the so-called espresso coffee prepared by blending a coffee fine powder and high-temperature water under pressure in a brewer assembly 22 and then extracting only a liquid therefrom, and that the frothed milk supplied from the milk tube 100 is prepared by mixing a programmed mixture of air, steam and milk with froth.
In addition, Patent Literature 2 discloses a technique by which a milk concentrate or a coffee concentrate is mixed with water using a venturi chamber, which flows together to a whirl chamber, and is beaten in the whirl chamber to form frothed milk or cafxc3xa9 creme. Further, Patent Literature 3 discloses, as shown in FIG. 5, a technique by which coffee ground using a brewer assembly 14 is processed to prepare an espresso liquid, and a measure of the espresso liquid is delivered together with steamed and/or frothed milk to a cup 21 to provide cafxc3xa9 latte or cappuccino.
[Patent Literature 1]
U.S. Pat. No. 5,207,148
[Patent Literature 2]
U.S. Pat. No. 6,183,800
[Patent Literature 3]
U.S. Pat. No. 6,019,032
Conventionally, however, there are some problems in making a coffee beverage in the above-mentioned cases. When cream is added to brewed coffee, or when coffee and a milk ingredient are mixed in advance to prepare cafxc3xa9 au lait, cafxc3xa9 latte or cappuccino, xe2x80x9cunturbid dark brown colorsxe2x80x9d inherent in a coffee liquid becomes whitish, and the appearance of the coffee is thereby damaged. Besides, adding cream or a milk ingredient can add mildness and robustness to the inherent taste of the coffee liquid, whereas the coffee comes to smell too milky, which deteriorates its aroma.
As described above, none of the conventional methods is capable of producing an easy-to-drink coffee beverage obtained by giving mildness and robustness to a coffee liquid without destroying the color, luster and aroma of its own, because even a slight amount of cream or milk would cloud the coffee liquid and thereby destroy its appearance.
The present inventor has researched and studied strenuously by trial and error to find a method for producing a coffee beverage by which mildness and robustness may be given to a coffee liquid without destroying the color (unturbid dark brown color) and aroma that are original to the coffee liquid. During the research, a variety of dairy products were compared and examined, including xe2x80x9cdry whole milkxe2x80x9d made by powdering milk, xe2x80x9cpowdered formulaxe2x80x9d, made by conditioning proteins and fats in milk to be small enough to be easily absorbed by babies and blending necessary nutrients without excess or shortage, xe2x80x9cCreapxe2x80x9d (registered trademark), one of the instant cream powder products in Japan, which is predominantly composed of cream to which skim milk and the like are added, xe2x80x9cskim-milk powderxe2x80x9d made by removing cream components from milk and powdering it, which has almost no milk fat and is rich in calcium and proteins. As a result of the comparison, it was found that the skim-milk powder was made by removing cream components from milk.
After a continued study and research based on such a finding, it was further found that, if a skim-milk powder dissolved in cold or hot water is frothed, and only a layer of the froth is mixed with a supernatant fluid or froth of freshly brewed coffee, mildness and robustness may be given to the brewed coffee to provide a coffee beverage without destroying the color, luster and aroma that the coffee originally has. In other words, it was found that, if a supernatant fluid or froth of freshly brewed coffee is mixed with froth made by frothing a skim-milk powder with water, the skim-milk powder froth changes into creamy fine froth having a light, lustrous brown (maroon) color, as if it absorbed only the color components of the brewed coffee, without clouding xe2x80x9cunturbid dark brown colorxe2x80x9d that the brewed coffee originally has. In addition, it was also found that the skim-milk powder froth adds mildness and robustness to the taste of the brewed coffee while eliminating a milky smell.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a method for producing a coffee beverage by which mildness and robustness may be added without destroying the color, luster and aroma intrinsic in freshly brewed coffee. Thus, the present invention may provide a breakthrough production method intended to make a coffee beverage easy to drink while bringing out the intrinsic taste of authentic coffee of various brands to advantage through a quick and easy approach.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, a method for producing a coffee beverage comprises a coffee liquid preparation step of brewing coffee or preparing a coffee liquid using cold or hot water and at least one of coffee beans ground up into appropriate grain size, a coffee concentrate and a coffee powder, and pouring the coffee liquid into a container, a frothing liquid base preparation step of mixing a skim-milk powder and cold or hot water to obtain a frothing liquid base, a frothing step of conducting, a frothing process on the frothing liquid base to form a froth layer on a surface of the liquid base and a mixing step of mixing froth of the froth layer with a supernatant liquid or froth of the coffee liquid to make the froth of the froth layer take on a consistent brown color.
According to the method for producing the coffee beverage consistent with the present invention, a skim-milk powder and water are blended, and a frothing process is then performed to form a froth layer on the surface of the mixture, so that the froth of that layer is mixed with a supernatant fluid or froth of brewed coffee so that the froth may take on a consistent brown color, thereby producing a coffee beverage with mildness and robustness without ruining the lustrous color and aroma of the brewed coffee. In addition, according to the method for producing the coffee beverage consistent with the present invention, bitter, hard-to-drink coffee may be made a suave, easy-to-drink coffee beverage through a quick and easy approach.